Product Description

The Multiple DAC645 is a dual version of the Hytec DAC640 which has 16 channels. Therefore it offers 2 x 16 channels and is a single width CAMAC module which provides 32 programmable analog outputs. Each output has a 12 bit resolution. The DAC is programmed by two 16 word, 12 bit stores, which may be overwritten and read via the dataway.

A single command allows all the outputs to be enabled (F25,A15+F25,A15) or disabled (F24,A15). Alternatively, each bank may be selected separately by a sub–address. On power–up all outputs are disabled, they are also disabled by Z.S2.

The unit features good temperature stability which is typically better than 10ppm/deg C. The outputs will drive up to +/–10v into 1K ohm load and +/–5v into 500 ohms, are short circuit protected.

The analog putput voltages are driven from two sets of 16 sample and hold circuits which are fed from two DAC’s via a 16 way multiplexer, which continuously scans the memory updating the analog outputs. To alter the value of any channel a simple overwrite command is executed and after a delay of not more than 1.6mS on the +5V range and 3.2mS on the +10V range. the output is set to the new value. The output range is link selectable for each group of 16 channels.

Provision has been made so that data codes of all outputs may be selected by CAMBION links, the operations are straight binary, 2’s complement binary and offset binary.

Features

• Single width CAMAC module.
• 32 Analog outputs.
• Low cost per channel.
• 0v to +/-10v into 1K ohms min. Analog O/P voltage.
• 0v to +/-5v into 500 ohms min. Analog O/P voltage.
• Low T.C. 10ppm typical 20ppm max.

Output Socket & Specification Details

• 2 x Cannon sockets type D 37–way.
• Non–linearity +/–0.5 LSB (referred to full scale).
• Zero offset +/–500mV max.
• Optional data codes.
• Up–date time 100mS min. 1.6mS max +5V range, 100mS–3.2mS on the +10V range.

Analog Reference Input

There is one on each set of 16 channels, this may be selected by Cambion link. It is used to reference all the analog outputs to a common earth reference. It must be with +/–2v of the modules’s earth line at all times. It helps with earth loops. It may be connected to a low resistance bias chain and used as an external common zero offset.

Temperature Range

0 deg C. to 50 dec C. Blown CAMAC crates are recommended.

Temperature Coefficient

Voltage outputs 10ppm typical 20ppm/deg C max.
Current Outputs 20ppm typical 20ppm/deg C max.
Try to avoid high output currents 10mA max.